21084145 has 8 divisors (see below), whose sum is σ = 25346304. Its totient is φ = 16837104.

The previous prime is 21084139. The next prime is 21084187. The reversal of 21084145 is 54148012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21084145 - 2⁵ = 21084113 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 439 + ... + 6508.

It is an arithmetic number, because the mean of its divisors is an integer number (3168288).

Almost surely, 2^21084145 is an apocalyptic number.

It is an amenable number.

21084145 is a deficient number, since it is larger than the sum of its proper divisors (4262159).

21084145 is an equidigital number, since it uses as much as digits as its factorization.

21084145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7559.

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 21084145 is about 4591.7474887019. The cubic root of 21084145 is about 276.2604181080.

The spelling of 21084145 in words is "twenty-one million, eighty-four thousand, one hundred forty-five".